A couple of these have been Mythbusters edutainment TV show topics. I am almost certain both the pigeons and the balloon have been on the show. I'm not sure h

A couple of these have been Mythbusters edutainment TV show topics. I am almost certain both the pigeons and the balloon have been on the show. I'm not sure how they'd use explosives to test the pigeon one, but I'm sure it would be interesting to watch. (edited to add, I just figured it out, they'll put frozen chicken parts from the supermarket in a really big box on top of some explosive, and put the works on a scale...) The iron bars is more fun when analogized to the famous barometer building height challenge where the goal isn't someones abstract idea of simplest but to come up with the most unusual way to determine the answer (for the barometer I like the idea of tossing it off the roof and timing the impact, or bribing the building superintendent with a really nice barometer). For the iron bars I think a funny way to solve the problem is to heat one bar above the curie point and after it anneals back to room temp, if the bars don't stick to each other I guess the heat treated bar WAS a magnet. Another fun trick if you don't trust your string suspension to not bias the hanging position WRT north pole, simply spin each bar in each axis and one bar will have a funkier deceleration curves for various axes.